This invention relates to a method of crimping and connecting a terminal to a conductor of a wire by pressing and compressing the terminal together with the conductor by the use of crimpers.
When a terminal is crimped to a conductor exposed at an end portion of a wire, the conductor is pressed and compressed together with the terminal and therefore is crushed to be extended toward an end thereof. When the conductor was thus crushed to be narrowed, a sufficient fastening force may not be obtained by the pressing and compressing operation and that a mechanical strength might be lowered. Therefore, as disclosed in Patent Document 1, there has been proposed a method of suppressing the crushing of element wires at the time of crimping a terminal to the conductor exposed at an end portion of a wire, with the conductor held between a pair of crimping piece portions of the terminal.
Among terminal press-crimping methods of the type described, there is one in which a terminal and a conductor are crimped together under pressure by using a plurality of crimpers (see Patent Document 2). In the method of Patent Document 2, all of division crimpers arranged in juxtaposed relation in an axial direction of a wire are pressed down to the same height to crimp the wire and a conductor crimping portion of the terminal together uniformly as a whole, and then part of the division crimpers is further pressed down to press a localized portion of the conductor crimping portion more strongly, thereby crimping the terminal to the wire.
In order to enhance contact reliability, a post treatment such as the coating of a coating agent is applied to the terminal and the conductor integrated with each other by the crimping connection. However, when the outer shape of the terminal and conductor crimped together became complicated, for example, because of spreading of the distal end of the crimped conductor or of the formation of irregularities such as convex and concave portions on the face of the terminal, it is difficult to effect the post treatment evenly over the entire area, and also a projecting portion of the terminal is liable to be caught by a connector housing at the time of mounting the terminal in the connector housing.
In the method described in Patent Document 2, the terminal can be strongly crimped and connected to the conductor while suppressing the forward extending of the conductor and the narrowing thereof, the technique of Patent Document 2 is not sufficient to simplify the outer shape of the terminal integrated with the conductor by the pressing and compressing operation.    [Patent Document 1] Japanese Patent Publication Number 2007-012341    [Patent Document 2] Japanese Patent Publication Number 2008-181695